All about Kina

Kina, the sea urchin Evechinus chloroticus, is a common and thought after seafood species in New Zealand’s kelp forest. Above a critical density the hungry herbivores rapidly turn thriving underwater forests into rock barrens. Why do kina numbers seemingly explode? It’s due to a lack of natural predators caused by overfishing of crayfish, snapper and other large finfish species.

Photogrammetry and Transects

A drastic change in the kina population and seaweed coverage at a popular dive site at Kapiti Island shook us up in March 2021. The conditions were good shortly after, so we returned with the Guardians of Kapiti Island Marine Reserve and a plan to use different methods for documentation.

Visibility at Kapiti Island is in general better than in Wellington harbour and we were able to build photomosaics of larger areas from our video footage. This method proved useful for sections of reef with reduced kelp coverage and barren patches. 

We also conducted counts along the transect tapes to get a more accurate picture of kina numbers. In areas with kelp coverage kina are often well hidden and divers have to get under the kelp canopy and right down to the holdfasts for counting. 

You can find details on the monitoring methods and download the monitoring report for the dives at Kapiti Island and Pukerua Bay from March 2021 here:

Photomosaic of a 25m transect at Kapiti Island

We captured another photomosaic at Pukerua Bay in March 2021.

Pukerua Bay Photomosaic

Wellington's Big Kina Count - Get Involved!

Help us understand the kina population at the northern tip of the Miramar Peninsula! You can join the count with one of the local dive shops or the Wellington Underwater Club!

Find out more and join the Big Kina Count!